为满足对振动环境下10 Hz以下低频小量程加速度信号的高精度测量需求,提出了一种基于石英微工艺的新型窄带宽MEMS加速度计,其敏感元件采用变间距式差分电容梳齿结构。采用有限元分析手段,对敏感元件质量块尺寸、梳齿长度、U型梁刚度、盖板结构、阻尼和带宽等参数进行了综合优化设计。敏感元件采用石英晶片经湿法腐蚀体工艺制作,加速度计样机经过了实际性能测试和环境适应性试验,带宽为8.9 Hz,非线性度约为0.7%,可以满足飞行器小量程低频加速度参数的测量需求。%To fulfill the high precision measuring requirement of minor acceleration signals which are lower than 10 Hz in high vibration environment,a novel quartz micro-machined accelerometer is presented,which detecting part has a comb finger symmetry structure and differential capacitance varies with the distances between detecting elec-trodes. The parameters including mass size,comb finger length,elastic beam stiffness,cover structure,air damp and bandwidth are synthetically designed and optimized with finite element analysis. The accelerometer is fabricated withα-quartz crystal on the base of bulk wet etching micromachining technique. The principle prototype was tested to ob-serve its actual capability and environment adaptability. Testing results shows that the accelerometer has an 8.9 Hz bandwidth and a 0.7% nonlinearity,and can suffice the measurement of the low-gn and low-frequency acceleration parameters for aircraft.
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